commit 17d56c24c10ed300233164cc51380979124d6dd8
Author: erouault <erouault>
Date:   Sat Dec 3 12:19:32 2016 +0000

    * tools/tiffcrop.c: add 3 extra bytes at end of strip buffer in
    readSeparateStripsIntoBuffer() to avoid read outside of heap allocated buffer.
    Reported by Agostino Sarubbo.
    Fixes http://bugzilla.maptools.org/show_bug.cgi?id=2621

diff --git a/ChangeLog b/ChangeLog
index d6a416b..50db803 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,12 @@
 2016-12-03 Even Rouault <even.rouault at spatialys.com>
 
+	* tools/tiffcrop.c: add 3 extra bytes at end of strip buffer in
+	readSeparateStripsIntoBuffer() to avoid read outside of heap allocated buffer.
+	Reported by Agostino Sarubbo.
+	Fixes http://bugzilla.maptools.org/show_bug.cgi?id=2621
+
+2016-12-03 Even Rouault <even.rouault at spatialys.com>
+
 	* tools/tiffcrop.c: fix readContigStripsIntoBuffer() in -i (ignore) mode so
 	that the output buffer is correctly incremented to avoid write outside bounds.
 	Reported by Agostino Sarubbo.
diff --git a/tools/tiffcrop.c b/tools/tiffcrop.c
index bdcbd63..9122aab 100644
--- a/tools/tiffcrop.c
+++ b/tools/tiffcrop.c
@@ -1,4 +1,4 @@
-/* $Id: tiffcrop.c,v 1.47 2016-12-03 11:35:56 erouault Exp $ */
+/* $Id: tiffcrop.c,v 1.48 2016-12-03 12:19:32 erouault Exp $ */
 
 /* tiffcrop.c -- a port of tiffcp.c extended to include manipulations of
  * the image data through additional options listed below
@@ -4815,10 +4815,17 @@ static int readSeparateStripsIntoBuffer (TIFF *in, uint8 *obuf, uint32 length,
   nstrips = TIFFNumberOfStrips(in);
   strips_per_sample = nstrips /spp;
 
+  /* Add 3 padding bytes for combineSeparateSamples32bits */
+  if( (size_t) stripsize > 0xFFFFFFFFU - 3U )
+  {
+      TIFFError("readSeparateStripsIntoBuffer", "Integer overflow when calculating buffer size.");
+      exit(-1);
+  }
+
   for (s = 0; (s < spp) && (s < MAX_SAMPLES); s++)
     {
     srcbuffs[s] = NULL;
-    buff = _TIFFmalloc(stripsize);
+    buff = _TIFFmalloc(stripsize + 3);
     if (!buff)
       {
       TIFFError ("readSeparateStripsIntoBuffer", 
@@ -4827,6 +4834,9 @@ static int readSeparateStripsIntoBuffer (TIFF *in, uint8 *obuf, uint32 length,
         _TIFFfree (srcbuffs[i]);
       return 0;
       }
+    buff[stripsize] = 0;
+    buff[stripsize+1] = 0;
+    buff[stripsize+2] = 0;
     srcbuffs[s] = buff;
     }